Decrypter can't compress, you have to use another program. Shrink 3.2 is the best of the freebies and you can burn with decrypter.

Nero recode works almost exactly like and as well as shrink but is much faster. It also comes with a bunch of audio/video programs and other stuff as well in the Nero Ultra 6 suite. You can use the trial version of Ultra 6 indefinitely til you decide to buy. You must reload and reinstall every month(the 22nd to the 22nd) and it's good for that entire time.

The easiest, fastest, and best is (IMHO) Intervideo DvdCopy 3. Even at level 2(out of 6), the quality is excellent. It has a 2 week trial version, I'd recommend giving it a try.

Only Rebuilder/CCE basic beats it for quality, but it isn't for the beginner and it takes about 3-4 hours. There are guides for all.